Asynchronous serial data communication has long been used to transmit data measured or generated at one device to another device for processing, storage or display. Multiple standards exist for specifying the transmission characteristics, or line settings, of serial data communication. Such characteristics include electrical form, data rate, data formats, error checking protocols and control mechanisms. In order to achieve proper data communication between a transmitting device and a receiving device, each device must use the same characteristics.
As a result, transmitting and receiving devices are often manufactured to accommodate multiple standards, thereby providing flexibility to allow a specific device to be set to operate under varying conditions with many different independent transmitting and receiving devices. In operation, the receiving device must be set to match the specific serial data communication characteristics in use by the transmitting device. Selection from the range of available options is customarily made by a user or installer at the receiver who has been advised in advance of the standard being employed by the transmitter. The user selects the options for the receiver by setting switches or jumpers, entering commands from a keyboard, or using a software program which mimics keyboard commands.
Thus, the flexibility to select and set serial data communication characteristics of one receiving device usually requires that the user or installer know the transmission characteristics used by the transmitting device and know how to set these characteristics in the receiving device.
Often, the asynchronous serial data communication characteristics are not known or easily determined, making installation and setup difficult, risking incorrect data communication. Setup varies from device to device, adding to the difficulty in making the receiving device operational with the correct characteristics. If the settings specifying the asynchronous serial data communication characteristics are not correct, the receiving device is not able to receive data properly.